Fuse cutout



n 1940- G. cARusLE FUSE CUTOUT Filed Jan. 31, 1956 2 Sheets-Sheet 1 June '11, 1940. CARLISLE 2,204,298

FUSE CUTOUT Filed Jan. 31, 1935 2 Sheets-Sheet 2 Hammad.

Patented June 11, 1940 UNITED STATES FUSE CUTOUT George L. Carlisle, Greensburg, Pa., assignor, by mesne assignments, to Railway and Industrial Engineering Company, Greensburg, Pa., a corporation of Delaware Application January 31, 1936, Serial No. 61,830

27 Claims.

This invention relates to fuse cutouts and more particularly to enclosed distribution cutouts and to repeating fuse cutouts.

An object of the invention is to provide a fuse 5 cutout in which the fuse assembly is detachably supported on the terminal assembly and has a pivotal movement upon the blowing of the fuse, the mounting elements being such that the fuse assembly cannot be inadvertently separated from the terminal assembly. An object is to provide an enclosed fuse cutout of the type in which the fuse is mounted on the pivoted door of the housing, and the pivotal supports of the door are so shaped that the door cannot be inadvertently separated from. the housing during either the opening or closing of the door. A further object is to provide a repeating fuse cutout including a plurality of terminal and fuse units, only one unit being normally in the circuit and each unit except the last including a switch member operated automatically upon the blowing of the fuse of that unit to connect an adjacent unit into the circuit.

These and other objects and advantages of the invention will be apparent from the following specification when taken with the accompanying drawings in which:

Fig. 1 is a central vertical section through an embodiment of the invention;

Fig. 2 is a fragmentary view showing the door in open position after the blowing of a fuse, the door being shown in side elevation;

Fig. is a similar fragmentary view of the door and fuse assembly in an intermediate posi- 5 tion as it drops open;

Fig. 4 is a perspective view of the lower terminal jaw;

Fig. 5 is a vertical section through a repeating fuse cutout embodying the invention;

Fig. 6 is a front elevation of the same as seen with the door and fuse assemblies removed;

Fig. 7 is an enlarged sectional view of the lower terminal and plunger switch of the repeater unit; and

Fig. 8 is a front elevation, partly in section, of the same elements.

in the drawings, the reference numeral i identifies the housing of insulating material, preferably porcelain, which has a bracket 2 for mounting the cutout upon a support and, preferably, inclined forwardly at an angle of about 15 to the vertical. A transverse rib 3 extends across the interior of the housing to increase the leakage distance between the upper jaw and the lower hinge terminals. The jaw terminal includes the hemispherical contact 4, of hard drawn copper, which is supported by and backed up with bronze spring strips 5 which are secured to the housing i by an embedded bolt 6 and a copper stamping I of approximately E-shape,

the central portion 8 being reversely bent to provide a stop for the fuse assembly and door, and the outer legs 8' being bent forwardly and threaded. to receive screws of a clamping bridge plate 9 by which a line conductor is secured to the jaw terminal. The hinge terminal, Fig. 4, is an approximately U-shaped stamping of copper or bronze having a central section which is secured to the embedded bolt 6' of the housing, the inclined flange ll of the central section being threaded to receive screws of the bridge plate 12. The legs l3 of the jaw terminal are parallel and slotted to form hook terminals for receiving the door and fuse assembly. The lower portions of the slots M are of circular oross-sec-= tion, but the upper portion of each slot is of less width with its rear edge tangent to the circular openings.

The door 15 fits within the side walls of the housing and is preferably a molded synthetic resin having high dielectric and mechanical strength, the door being of dished form and having an integral pull ring IS. The expulsion tube i! of insulating material is fixed in an upper apertured collar 18 of copper or bronze which is grooved to receive straps 19 that are secured to inner flanges 20 of the door by screws 2|. The lower end of the tube l1 rests upon a correspondingly shaped rib I of the door and carries a conducting collar 22 to which the U- shaped bracket 24 is pivoted by a pin 25 which preferably extends through the inner edge of the tube H to lock the collar 22 to the tube. A pivot pin 26 extends through the bracket 24 and is fixed therein to face the flatted surfaces 26 of non-circular pin ends downwardly and approximately normal to the plane of the door when the fuse assembly is in operative position.

The fuse element may be of any desired type but is preferably an explosive fuse of the ignition, as distinguished from the fusion type. As shown in Fig. 1, the fuse element includes a disk head 2'! to which a thin metal strip 28 is secured, the strip being notched to provide a restricted' zone that will be heated to the ignition temperature of an explosive, such as black powder, by current flow in excess of a predetermined value. The notched section of the strip is housed within a glass tube 29 that is filled with black powder, and a flexible conductor 30 is soldered to the lower exposed end of the strip 28.

The assembly is placed in operating condition by inserting the fuse element through the apertured collar i8 at the upper end of the tube, and clamping the disk head 21 against the collar It, or against an inserted washer 3|, by the closure cap 32 which may be knurled and provided with a kerf for threading the same upon the collar I8. The outer end of the cap 32 is the passages M of the lower terminal i3.

preferably rounded and slightly recessed at the top to receive the lower part of the terminal jaw member 2 when the door is fully closed. The flexible end 35! of the fuse element is then passed around the bolt 33 which is fixed in the pivoted bracket 26- and is drawn tight to force the bracket tightly against the tube i1 before the wing nut 3 3 is tightened to lock the parts in this normal position.

This re-fusing is performed with the door 25 separated from the housing i, and the door is then mounted upon the hinge terminal by lifting the door, when in approximately horizontal position, to engage the ends of pivot pin 26 in The lower end of the door passes below the hinge :et in this operation and the fiat sides 26 of the pivot pins strike the back walls of pas- M. The pins 26 will slide down the passages only when the fiat surfaces 26 are substantially in full surface contact with the passage walls, i. (2., when the door is approximately horizontal. The natural motion of lowering the door after the pins engage in the slots will necessarily result in the proper moiuiting of the door, but the sliding fit of the pin ends in the slots prevents any false movements which might tend to disengage the door and, when the pins reach the circular ends of the slots, a slight Y angular movement of the door definitely locks turns the door about the lower terminal to force the end of the tube cap 32 under the jaw terminal 4. The rounded surface of contact 4 seats within the depression in the cap 32 and the spring pressure yieldingly locks the fuse assembly and door in closed position. The door may be opened manually, if desired, but it cannot drop into open position so long as the fuse link is unbroken. When the fuse blows, the bracket free to turn on the pin 25 and the approximately axial pressure exerted along the expulsion tube by the springs 5 of the jaw terminal forces the door downwardly and outwardly, see Figs. 2 and 3. It will be noted that the rebound of the door from its dropped position cannot lift the pivot pin 26 out of the hinge terminal since the full diameter sections of the pin ends are presented towards the narrower slots M before the dropping of the door creates an upward reaction. The door is readily removed for refusing, however, since pressure at the pull ring it, exerted outwardly and upwardly, naturally results in an alinement of the flattened surfaces with the rear edges of slots l4 and a lifting of the pins along the slots.

The repeating cutout shown in Figs. 5 to 8 includes two units which, in general, may be substantially identical with the described constructions. The terminal constructions will not be described again but the several parts are identifred by the reference numerals of Figs. 1 to 4.

The housing 3| is formed into two compartments by an integral interior wall 32 that terminates at or about the upper edges of the lower hinge terminals. Both the exterior walls and the interior wall 32 have alined openings 33 through which a line conductor extends and is clamped to the terminal extensions 8. Only the right wall has an opening 34' for the branch line that is to be clamped to the plate ll of the hinge terminal of the right hand unit. The

clamping strip i2 is omitted from the other hinge terminal as the branch line is to be connected to the left hand unit only when the right hand fuse blows. The two compartments have separate doors i5 and fuse assemblies.

The switch mechanism for automatically cut-- ting in the second fuse comprises a spring jaw contact 35 that is riveted or otherwise secured to a leg i3 of the left hand. hinge terminal and plunger switch that is mounted on a supporting arm 36 and a guide arm 3'1 that are riveted to the legs i3 of the other hinge terminal.

This plunger switch, as shown in Figs 7 and 8, comprises a tube 38 that is mounted on arm 36 and a plunger or outer ube 39 that telescopes over the inner tube 38 to slide through the guide arm 31. The plunger is urged towards the left and also in a counterclockwise direction, 5, by a coil spring 40 that is secured between the outer end of the plunger 39 and a plug ll that closes the tube 38. A braided conductor 42 extends through the tubes and is soldered to the plunger head and to plug 4! to act as a low resistance jumper. A sleeve 43 is fixed to the plunger 39 near its ri ht end and has a radial lug 44 that is normally engaged in a notch 45 in the center plate iii of the hinge terminal. The front portion of the sleeve 43 has an extension 43 to which a handle 4'! of insulating material is secured.

As shown in Fig. 5, the handle 41 extends into the path of movement of the door l5 when it drops to open position upon the blowing of the fuse. The handle is thus turned clockwise to release the lug 44 from the notch 45, and the spring 40 throws the plunger towards the left to in the jaw member 85, shown in dotted lines in Fig. 6. Ihe branch line is thus reclosed after the blowing of the first fuse, but is left open if the second fuse blows. may be re-fused either before or after the second fuse blows. In either case, the handle 41 moved to the right and lifted to lock the lug 44 in the notch 45 when both fuse units are in operating condition.

The illustrated arrangement of the contact jaw 35 of the plunger switch restricts the construction to a double fuse system but it will be apparent that a greater number of units may be used in a repeater cutout by mounting the contact jaw 35 on the supporting arm 36 of a plunger switch, the fuse units of this type being brought into the circuit by the blowing of the adjacent fuse to the right and, in turn, operating their own plunger switches to connect the next adjacent fuse to the left into the circuit. Obviously, too, other types of latched switches may be used in place of the illustrated plunger type of switch.

It will be understood that the embodiments herein described are illustrative of the invention and that various changes may be made in the several parts, their size, shapes and relations, without departing from the spirit of my invention as set forth in the following claims.

I claim:

1. A fused cutout comprising a fuse assembly including a fuse element extending through an expulsion tube and electrically connected between conductive members on opposite ends of said tube, trunnions carried by the lower conductive member, a lower hinge member for detachably receiving said trunnions, and an upper jaw terminal having a rigid current carrying contact portion of approximately spherical contour, and spring The first unit means supporting and pressing the contact portion upon and substantially axially of the upper conductive member of the fuse assembly.

2. In a fused cutout, the combination with a fuse assembly comprising an expulsion tube, conductive members secured to the opposite ends of said tube, fuse means extending through said tube, a cap on the upper member for retaining the fuse means in contact therewith, said cap having a concaved upper surface, means for electrically connecting the lower end of said fuse means to the lower conductive member, and mounting means at the lower end of the fuse assembly, of a lower terminal for detachably re-- ceiving said mounting means, an upper jaw terminal including a convex contact portion for em gagement with the concaved upper surface of said cap, and spring means for pressing said terminals towards each other, thereby yieldingly to retain a fuse assembly in operative position between said terminals.

3. In a fused cutout, the combination with a fuse assembly comprising an expulsion tube for mounting in approximately vertical position and having conductive members secured to the opposite ends thereof, mounting means carried by the lower member, fuse means extending through said tube and electrically connected to the lower conductive member, a cap member for retain ing the upper end of the fuse means in contact with the upper conductive member, of a lower hinge terminal for detachably receiving said mounting means of the fuse assembly, and an upper jaw terminal having a rigid substantially spherical surface portion for engagement with said cap and spring means for supporting and yieldingly pressing said spherical surface portion against said cap when said fuse assembly is in operative position between said terminals.

4. In an enclosed fused cutout, the combination with insulated casing means, sets of upper and lower terminals supported by said casing means, means for electrically connecting one terminal of the first set to one side of a line and the second terminal of all sets to the other side of a line, a dropout fuse assembly normally con nected between the terminals of each set, and a casing cover secured to each fuse assembly and movable therewith between an upper operative and a lower inoperative position of the fuse assembly, of normally open switch means operative automatically upon the blowing of a fuse assembly to connect the first terminal of the set associated with the blown fuse to the corresponding terminal of the adjacent set, said switch means including a movable member electrically connected to said first terminal of the set associated with the blown fuse.

5. A repeating fuse construction comprising a first fuse unit and a second fuse unit, said first fuse unit having stationary contacts, said first fuse unit having a fuse tube provided with spaced contacts and having a fuse link electrically joining said spaced contacts, cooperating means on said fuse tube and said stationary contacts for holding said first fuse tube withitsspaced contacts in engagement with said stationary contacts so long as said fuse link remains intact, a casing for said first fuse unit provided with a door, said door being supported by said first fuse unit and movable outwardly by the outward motion of the fuse tube of said first fuse unit, an electric line normally connected through said first fuse unit, and switch means controlled by the position of the fuse tube of said first fuse unit for connecting the electric line through said second fuse unit when said first fuse unit has blown.

6. A repeating fuse construction comprising a first fuse unit and a second fuse unit, said first fuse unit having stationary contacts, said first fuse unit having a fuse tube provided with spaced contacts and having a fuse link electrically joining said spaced contacts, cooperating means on said fuse tube and said stationary contacts for holding said first fuse tube with its spaced contacts in engagement with said stationary contacts so long as said fuse link remains intact, a casing for said first fuse unit provided with a door, said door being supported by said first fuse unit and movable outwardly by the outward motion of the fuse tube of said first fuse unit, an electric line normally connected through said first fuse unit, and switch means controlled by the position of the fuse tube of said first fuse unit for connecting the electric line through said second fuse unit when said first fuse unit has blown, the fuse tube of said first fuse unit rocking downwardly to inoperative position automatically after the first fuse unit has blown.

'7. In a repeater fused cutout, the combination with two pairs of upper and lower terminals, means mounting said pairs of terminals in parallel and horizontally alined relation, spring pressed switch means on one lower terminal for closing a circuit to the other lower terminal and latch means normally preventing closing movement of said switch means, of a drop-out fuse assembly mounted on each lower terminal for engagement with the associated upper terminal, and means operable automatically upon the blowing of one fuse assembly to release the said latch means, thereby to permit the closing of said switch means.

8. A repeater fused cutout as claimed in claim '7, wherein said means for releasing the latch means is automatically operated by the blowing of the fuse assembly mounted on that lower terminal at which the spring pressed switch means is located.

9. In a fused cutout, two sets of upper and lower terminals, a fuse assembly pivotally mounted on each lower terminal and including means for automatically displacing the same from the associated upper terminal upon the blowing of the fuse, a movable switch member carried by one lower terminal, spring means for moving said switch member into electrical engagement with the next adjacent lower terminal, latch means normally preventing movement of the switch member towards operative position, and means actuated upon the displacement of the fuse as sembly in the lower terminal which carries the switch member for rendering the latching means inoperative.

10. In a repeating fused cutout, the combination with a support, a plurality of sets of upper and lower terminals carried by said support, and means on each lower terminal for receiving a drop--out fuse assembly, of normally open switch means for connecting adjacent lower terminals, spring means urging the movable member of each switch means toward closed-circuit position, means latching each movable member in open circuit position, and means actuated by the dropping of a fuse assembly on one lower terminal to release the associated movable member from said latching means, whereby said spring means is operable to close the switch means between that and an adjacent lower terminal.

11. A repeating fused cutout as claimed in rift w,

claim 10, wherein d switch means includes a switch member on ied by one lower terminal and yieldingly urged toward a contact member carried by 'tl adjacent lower terminal, and l' -ch means ncxnally preventing movement of switch n iber, said switch member having a latch--eleasing portion extending into the path of movement of the associated fuse assembly as it drops to open position.

12. An automatic repeater fuse of the type including a pair of fuse units each normally retained in operative position beof upper and lower terminals, an ally connected through the ui it, men; f releasing the first fuse nnai when that fuse unit upon the blowing unit for connecting the lower ized by the fact that said "e ct member and a contact tively by the lower terminals of the means for connecting the jaw terminals in parallel and means for connecting the hinge of the first fuse unit to the circuit to be protected, both of said fuse units being normally mechanically held in operative position between t e associated terminals, means for releasing the first fuse unit from its jaw terminal upon blowing of said first fuse unit, switch means including a contact member supported on the hinge terminal of the first fuse unit and a cooperating contact on the other hinge terminal, means latching said switch means in open position, and means operable upon the blowing of the first fuse unit for rendering said latching means inoperative.

14. In a repeater fuse, an insulating support and pairs of fuse supporting terminals carried thereby, seats on all corresponding terminals except the first for receiving a contact member, and a contact me aber carried by each of said corresponding terminals except the last adapted to engage the contact seat of the next adjacent terminal, spring means tending to move each contact member to engage its associated seat, and means latching each contact member to its associated terminal in position to be displaced from its latching means for movement by its spring means upon the blowing of a fuse connecting the 'erminal of that contact arm to its associated terminal.

15. A repeater fuse assembly of the type including a plurality of drop-out fuse assemblies normally retained in operative position between pairs of upper and lower terminals, and means for successively connecting said fuse assemblies into a circuit as the fuse element of each fuse assembly except the last is blown, characterized by the fact that said means includes a plurality of normally open switches for successively connecting each lower erminal to the next adjacent lower terminal, means tending to close said switches, means latching said switches in open position, and means operable by each fuse assembly except the last as it drops to open circuit position to render the latching means of the associated switch inoperative.

16. In a repeater fuse, a plurality of sets of hinge and jaw terminals, fuse assemblies equal in number to the sets of terminals, means on each hinge terminal for rernovably receiving and pivotally supporting a, fuse assembly, means on each jaw terminal for engaging the associated 5 fuse assembly to hold the same in elevated posi tion only so long as the fuse e ement thereof doec not blow, and switch means operable upon the dropping of a fuse assembly when the fuse clc-- ment thereof blows for serially connecting the 10 hinge termials to each other; said switch means comprising a plurality of switches equal in num ber to one less than the number of sets of terminals, each switch including a movable contact carried by each hinge terminal except the 15 last, contact seat ca ried by each hir' e "1* minal except the first, springs means no' urging each movable contact tows" .i tact seat, latch means normally preventing spring means from moving the contact of each 20 switch towards its associated seat, and n operable by each fuse assembly exc 'h as it drops to open circuit position to latch means of the associated switch contact "ii operative, thereby permitting said spring means to move that switch contact to its seat on the adjacent hinge terminal.

17. In a repeater fuse assembly, vertically disposed insulator means, a plurality of jaw terminals mounted at the upper end of said insulator 30 means and electrically connected to each other,

a plurality of hinge terminals mounted the lower end of said insulator means and i, jul'fttz i l from each other, a drop-out fuse assembly supthereby in engagement with the correspimding jaw terminal only so long as the fuse elem nt of the fuse assembly remains intact, a pin: of switches each including a contact member carried by one hinge terminal and a seat member carried by the next adjacent hinge terminal, means latching each contact member to the hinge terminal carrying the same, means positioned to be engaged by the fuse assembly of each hinge terminal having a contact member for releasing the respective contact members from their latching means, and spring means for closing each contact member upon its seat member when released from its latching means.

18. A repeating fused cutout of the type ineluding a plurality of drop-out fuse assemblies each normally removably supported between an upper and a lower terminal, each fuse assembly being automatically released from its upper terminal and pivoting about its lower terminal into a dependent position when the fuse blows, a line conductor connected to all of the upper terminals, a circuit to be protected normally connected to only the first of the lower terminals, and switch means operable as each fuse assembly except the last is rendered inoperative for con-- necting the adjacent fuse assembly into the ch cuit to be protected, characterized by the fact that said switch means includes a contact member carried by each lower terminal except the last, a cooperating seat for each contact member on the next adjacent lower terminal, spring means operative continuously to urge the contact member of each switch towards its coop-crating seat, latch means normally preventing movcment of each contact member by its spring means, and means operable as each fuse assembly except the last drops to open position to release the associated contact member from its latch means, thereby permitting displacement thereof to engage its seat on the adjacent lower terminal.

19. In a repeating fused cutout, the combina tion of a plurality of sets of upper and lower terminals, means connecting all of the upper terminals in parallel, means on one lower terminal for making connection to the circuit to be protected, means on each lower terminal for receiving a drop-out fuse assembly, and a fuse assembly removably seated on each lower terminal and engaging the associated upper terminal so long as the fuse remains intact, of a switch member carried by each lower terminal except the last, means normally retaining each switch member in inoperative position on its own terminal, a cooperating switch seat for each switch member on the adjacent lower terminal, and means continuously urging each switch member towards its cooperating seat, said dropout fuse assemblies being operative upon blowing the fuse thereof to release the associated switch member for movement into the switch seat of the next adjacent terminal.

20. A repeater fuse assembly of the type including a plurality of drop-out fuses, sets of vertically spaced terminal means normally supporting said fuses in approximately vertical position, and switch means for successively connecting a fuse in the circuit as the next adjacent fuse blows; characterized by the fact that said switch means includes, for each fuse except the last, a switch arm mounted on a lower terminal means for movement in an approximately horizontal plane, and a seat for each switch arm on the next adjacent lower terminal means.

21. A repeater fuse assembly of the type including a plurality of sets of vertically spaced upper and lower terminals, means electrically connecting the upper terminals to each other, dropout fuse units mounted between the terminals of eachset, and switch means for successively connecting each lower terminal to the next adjacent lower terminal; characterized by the fact that said switch means includes for each lower terminal except the last a springpressed movable contact member and a seat for the same on the adjacent lower terminal, and means normally latching each contact member in open circuit position, said latch means ineluding a member engageable by the associated fuse assembly after the latter has moved through approximately its full range of drop-out movement to render the latch means inoperative, whereby the spring-pressed contact arm may move to closed circuit position.

22. In a repeating fused cutout, the combination with a plurality of sets of upper and lower terminals, and means on each lower terminal for receiving a drop-out fuse assembly, of a plunger carried by one of said lower terminals, spring means for pressing said plunger towards the adjacent terminal, and latch means releasable by the dropping of the associated fuse assembly for normally preventing movement of said plunger by its spring means.

23. A repeating fused cutout as claimed in claim 22, wherein said plunger is rotatable upon and telescoped over a tube housing the associated spring means; and said latch means comprises a lateral projection upon said plunger and normally engaged behind a stop member, and a trip member carried by said plunger and positending to effect relative rotation of said. tubular members in one direction, a latch member projecting from one of said telescoped members, a stop for engagement by said latch member to prevent relative longitudinal movement of said telescoped members, and a trip member mounted upon the said telescoped member which carries said latch member, said trip member being adapted to be displaced to rotate the associated telescoped member to release said latch member from the said stop.

25. In a repeating fused cutout including a plurality of sets of upper and lower terminals, a plunger switch adapted to be mounted on one lower terminal and operated to engage an adjacent lower terminal, said plunger switch including a pair of telescoped members, spring means tending to effect relative rotation of said telescoped members and to project one of the same into electrical engagement with an associated lower terminal, a latch carried by one telescoped member and normally seated adjacent a stop to prevent the said projection of one telescoped member, and a trip handle secured to one telescoping member to effect rotation of the same and release said latch from said stop.

26. In an enclosed fused cutout, the combination with a multiple compartment housing of insulating material, a pair of vertically spaced terminals in each compartment, a fuse assembly removably mounted on each lower terminal and normally in engagement with the associated upper terminal, means operable upon the blowing of the fuse of each fuse assembly to displace said fuse assembly from its upper terminal, closures for said compartments and including means for mounting the associated fuse assembly thereon, normallyopen switch means for connecting the lower terminals, and spring means operable by the blowing of one fuse assembly for actuating the switch means to closed circuit position.

27. In a repeating fused cutout, the combina tion with a pair of sets of upper and lower terminals, the lower terminals having means for pivotally mounting a fuse assembly, and fuse assemblies pivotally mounted on said lower terminals and. engaging the corresponding upper terminals, said fuse assemblies each including fuse means extending through an expulsion tube and means operable upon the blowing of said fuse means for moving said tube away from its associated upper terminal, of switch means comprising a movable member on one lower terminal, spring means for urging said movable member towards the other lower terminal, latch means normally operative to prevent movement of said movable member, and means operative upon the movement of the expulsion tube associated with the first lower terminal for rendering said latch means inoperative.

GEORGE L. CARLISLE. 

